This invention pertains to a check rail lock and keeper which except for the operating handle can be completely concealed within the check rails of the upper and lower sash of a double hung window. Each of the check rails is provided with a cavity with the cavity in the check rail of the lower sash receiving and enclosing a check rail lock housing having an exposed face and which rotatably mounts a locking cam operable by a rotatable shaft extending upwardly from the housing and having a handle at a level above the check rail associated with the rotatable shaft. A keeper is positioned in and enclosed in a cavity in the check rail of the upper sash at a location to permit the mounting of weather stripping and has downwardly inclined openings extending from the front face thereof enabling the insertion of fastening members into the check rail without interfering with window glazing. Other improvements and refinements are described hereinafter.
The concealed check rail lock has a number of components known in prior art structures and particularly as shown in my copending application Ser. No. 821,004 filed Jan. 22, 1986 now U.S. Pat. No. 4,736,972 granted Apr. 12, 1988. The prior check rail lock has a housing mountable to the top of a check rail and which mounts a rotatable shaft having a locking cam disposed internally of the housing and a handle secured to the shaft externally of the housing. A locking cam is rotatable between locked and unlocked positions as determined by limit stops within the housing and a spring detent washer detents the locking cam in either of these positions. A coacting keeper interengages with the locking cam in a locked position.